Certain cancers, such as prostate cancer, which is the second leading cause of cancer deaths among men, largely depend on androgens for their development and progression. Androgen effects in prostate and other tissues are mediated by the androgen receptor (AR). This protein binds to and is activated by androgens. The importance of the androgen receptor in the development of prostate cancer is demonstrated by the success of anti-androgen therapy at the early stages of prostate cancer. Hormone ablation therapies continue to dominate the market, as they have proven to be the most effective at treating the early stage prostate cancer, which is hormone-dependent.
However, this therapy and others currently used are ineffective against late-stage prostate cancer, which is hormone-refractory and usually lethal.